


it's the nature of the beast

by Overanalyzer



Category: Percy Jackson and the Olympians & Related Fandoms - All Media Types, Percy Jackson and the Olympians - Rick Riordan, The Heroes of Olympus - Rick Riordan
Genre: Alpha/Beta/Omega Dynamics, Dubious Consent, Implied Mpreg, Light Sadism, M/M, Mild Dehumanization, Rough Sex, Self-Esteem Issues, Suicidal Thoughts
Language: English
Status: Completed
Published: 2017-03-27
Updated: 2017-03-27
Packaged: 2018-10-11 15:41:45
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 4,241
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/10468428
Author URL: https://archiveofourown.org/users/Overanalyzer/pseuds/Overanalyzer
Summary: Leo might be the world's least likely Alpha. Jason's definitely the world's least likely Omega. Throw in some amnesia and work-related distraction, and you've got a perfect storm of unfortunate circumstances.





	

**Author's Note:**

> This was destined to happen sooner or later. Leo's my bicycle for this fandom, my love for bottom!Jason knows no bounds, and I'm a wordy motherfucker who constantly overthinks fetishy porn tropes. 
> 
> This takes place shortly after _The Lost Hero_ , with all the age-related not-so-goodness that timeframe entails. I'd apologize, but we all know this isn't the worst thing I've ever done.

" _Please_."

So, here's the thing about Leo Valdez: He really, really didn't have time for this shit.

Leo had never been interested in second genders (or castes, or breeds, or role dynamics or what the hell ever the term was these days that he was supposed to use). As kid, it had been assumed he'd present as a Beta, and he'd been content with that; nobody noticed Betas, which would have come in handy as a runaway.

Leo being Leo, luck wasn't on his side. So one day, Leo Valdez: malnourished 14-year-old street urchin and certified Least Aggressive Dude On Planet Earth woke up in a storm drain to discover that he was now Leo Valdez: Alpha, and life officially went off the rails (insomuch as life on the streets could go even further off the rails than it already had). Because now he wasn't just a homeless Mexican troublemaker in the eyes of The Law, oh no; now he was an untethered Alpha on top of all that. Because despite everything everybody said about how it was "an Alpha's World", the truth was that that really only applied if you were the Right Kind of Alpha (i.e., not like Leo).

And that was how Leo, now officially Threatening to good normal law-abiding folk and their sweet, innocent, and oh-so-vulnerable Omega children, had wound up in the Wilderness School in the first place. Which had actually...not been that bad?

Make no mistake, Leo resented the loss of his freedom (dirty and difficult, but it was his), and he super-duper resented being treated like a sexual predator in waiting, but three squares a day and central heating were hard to argue with. As were the suppressants. Leo was a _big_ fan of his suppressants.

Because ruts? **Sucked**. No matter what the hundreds of exabytes of porn on the internet said otherwise. That first rut, way back in Denver on the day he'd presented, had been hell on Earth. He'd gone to sleep wondering how quickly he could make it to St. Louis, and he'd woken up with the nearly overwhelming urge find the nearest warm body and get it pregnant. Not a good look on anyone, in his opinion, and a downright terrible one on Leo Valdez, previously established as the Least Aggressive Dude on Planet Earth.

So medication to regulate his hormones and limit his reaction to pheromones? That had been a damn good reason to stay in the system. Then the school bully turned out to be a literal monster, the gym teacher turned out to be a literal goat-man and Leo and his two best friends turned out to be the children of literal pagan gods. Monsters were killed, conspiracies were uncovered, a dragon was befriended and subsequently blown out of the sky, and it was only after all this bullshit that Leo realized one very important fact he'd been overlooking ever since the Grand Canyon: He'd left his goddamn pills in the Wilderness School dormitory.

The final detail to make this whole situation just perfect? He realized this .3 seconds after opening the door to Cabin 1 and finding Jason Grace in the middle of heat.

To be clear: Leo had come for the sole purpose of suggesting a few rounds of Mario Kart to take his mind off the logistical nightmare that was the construction of a flying warship. Had the Zeus cabin not been so well insulated, Leo would have turned around to notify an authority figure at the first whiff of Omega pheromones. But now...

Now Leo, his blood tragically free of any helpful foreign substances was in a confined space with a newly-presented (and very unlikely, _holy shit_ ) Omega who was putting out "come fuck me" pheromones with all the vigor of a body that still had no earthly idea what it was doing yet.

"Leo?" Jason's eyes were bloodshot and tearing up and weren't blinking as he stared at Leo from the bed. Jason was naked (and holy hell; Leo had known, objectively that Jason was attractive, but this was just unnecessary), with three fingers pumping in and out of his ass, wet with slick that Leo was certainly not paying any attention to.

And he was looking at Leo, like Leo was the answer to every prayer he'd ever had.

"Leo. I need..." This was bad. This was bad, because people like Jason did not look at people like Leo like that, except that that was a thing that was now happening, never mind how little sense it made. Jason was an Omega. Jason Grace was an Omega in heat and he hadn't prepared for it because he'd forgotten (' _thanks for absolutely nothing, Hera_ ,' he cursed), and Leo was an Alpha who wasn't prepared for it because he'd forgotten (' _thanks for absolutely nothing, Self_ ,' he cursed), and this. Was. Bad.

Leo's brain was rapidly being overwhelmed by the the aforementioned "come fuck me" pheromones, but there was a part of him that was resisting. This part, which he liked to call "Engineer Leo", was the bit that thought things through. It handled the cause-and-effect stuff that needed attention when you were building semi-sentient flying warships with dragon brains. "If A, then B", and that sort of thing. And right now, Engineer Leo was loudly screaming at the rest of Leo's brain to hold the fuck up, because there were sure to be consequences if Leo Valdez, an annoying nobody on his best day, was caught knotting Jason Grace, actual superhero.

Unfortunately, Leo reflected as he shut the door behind him and took a few halting steps forward, "come fuck me" pheromones were a whole hell of a lot more fun to listen to than one's own killjoy self-awareness, and he felt himself harden in his jeans (truthfully, he'd been hard since halfway through opening the door; this was just the first time he'd realized it). "Jason," he croaked, starting to sweat as the pheromones worked their physiological magic, "I"m not..." Because no matter what his body was doing (and what his stupid, stupid brain was going along with), Leo needed Jason to understand that he had no idea what the fuck he was doing. That this was all wrong, so that they both knew it and maybe later they could laugh about it if their friendship survived this incredibly ill-advised turn of events.

Sadly, “Sentence Fragments and Their Deeper Meanings 101” was apparently not a class they taught at Camp Jupiter, and Leo's plea was just met with another desperate groan and a quickening of Jason's fingers. Whatever objections Engineer Leo raised were crushed underfoot by Horny Leo, the devious son of a bitch, and Actual Leo was too busy looking at his Omega (soon to be his, anyway) to pay much attention at all to the hands moving of their own accord to unbutton his shirt. But Engineer Leo was not quite down for the count, and oh-so-helpfully noted that by now Leo was pumping out his own “Going to Fuck You” pheromones. It didn’t actually help (quite the opposite, actually, since the effect it was having on Jason was giving Leo quite the power trip), but it was a valiant effort, even if it did nothing to stop Leo from loosening his belt.

The impromptu strip show, clumsy though it was, seemed to do wonders for Jason’s already overwhelming libido. He pulled his fingers out of his ass as the flow of slick got even heavier, and spread his legs as far as they would go. He closed his eyes and threw his head back, the very picture of submission.

That, more than anything, sealed Leo’s fate. He was only human, after all (give or take whatever it was in his DNA that made him not actually human, of course), and there was only so much one idiot teenager could be expected to do in the face of this: a beautiful boy all laid out and begging to be bred like the little bitch he was. Kicking off his shoes and shoving his pants down, Leo practically leapt onto the bed, crawling on top of Jason and wasting no time in pressing their mouths together.

Jason was responsive. “Responsive” in this case meaning “wrapped his arms and legs around Leo while moaning like a wanton whore and grinding up against his Alpha”. Leo appreciated the sentiment, but it was a little too assertive for his tastes at the moment, so he responded like any good Alpha would: he roughly forced Jason’s shoulders back against the mattress and sunk his teeth into the bitch’s neck. Jason let out a cry that was two-fifths pain and three-fifths ecstasy, and the sound almost had Leo coming there and then. Fortunately for his dignity, he persevered, holding Jason’s body down with his own and savoring the blood on his tongue. Jason tasted good. Had he really been so committed to avoiding this?

Well, having now started to experience it, Leo could safely say _fuck that_.

“Turn over,” Leo growled, pulling away from Jason’s neck. His Omega hurried to comply, making sure to rub up against him for every second of it, the little slut. Leo expressed his totally insincere displeasure by slapping Jason’s ass. Jason moaned, and it was so pretty Leo slapped him twice more.

(Engineer Leo had long-since stopped trying to prevent the inevitable, and had turned his attention to coming up with designs to be used on Jason when the next heat rolled around. Concept #1: automated spanking machine.)

Rubbing his cock up against Jason’s slick ass, Leo relished the pained, needy gasps the motion elicited from the Omega. “Please,” Jason gasped, “please, Alpha…” He sounded so miserable, like every second he spent not getting knotted was the worst torture imaginable.

Unfortunately for Jason, Leo was in a torturing mood. “Please Alpha what?” he asked, his voice dripping with cruel amusement. He stopped grinding against Jason’s ass, and even mustered the willpower not to bite the back of his Omega’s neck. “You want something? Too fucking bad.”

Jason actually started sobbing. Leo ran his hand over the other boy’s face and was gratified to find it wet with tears. He brought the hand up to his face and licked it clean, relishing the taste. He was going to have to make Jason cry more often.

“Please,” Jason groaned, “I need…” Shit, he was really hurting for it.

“You need what, Omega?” Leo fully intended to draw out his bitch’s suffering for as long as possible. Never mind that he was beside himself with the need to fuck Jason; his Omega was going to _earn_ this.

“Your...your knot!” Jason cried. “I need your knot!”

All that earned him was another slap. “I need your knot…?” Leo prompted.

“I need your knot, Alpha!”

It was a little late, but Leo thought it merited a tiny reward. He pushed the head of his cock inside Jason, but no more than that, and got his own reward in the form of a slightly relieved but even more frustrated groan. Jason tried to push back, to get more inside him, but Leo had his hips in an iron grip, and the Roman was either unwilling or unable to use his considerable strength to break that grip. The thought sent a thrill up Leo’s spine; for all Jason’s power, he was here beneath him by choice. He wanted this. He wanted to be used.

Leo was all too happy to accommodate him.

“I’ll tell you what,” he offered, running his fingers through Jason’s hair, “I’ll give you a little more…” he tugged at the blond locks ever so slightly, “...if you make it worth my while.”

“What--uh--” Jason groaned as his hair was pulled, “--what do you want me to do, Alpha?” His whole body had gone limp; he’d stopped struggling, too overwhelmed by desperation to actually do anything about it. He had one cheek pressed against the sheet, just the right angle for Leo to see the occasional tear escape.

“Be honest. Did you know you were gonna go into heat today?”

“N-no, Alpha.” Jason’s face was already red with exertion and want, but he seemed to blush even deeper.

“Hmmmm…” Leo considered the answer, “...I’m not sure I believe you.”

“It’s true!” Jason cried.

Leo raked his blunt fingernails across Jason’s ribs; hard enough to sting, but not enough to break the skin. “Don’t lie to me,” he growled, enjoying the way his Omega shivered at his tone, “I think you planned this. You knew I was off my suppressants, and you were just waiting to get me here.” He delivered another smack to Jason’s ass. “Manipulative--” _smack_ “--little--” _smack_ “--bitch!”

Jason’s crying intensified as he rapidly shook his head. “No!” he protested, “I swear! I didn’t know!” Now he did start to struggle. It was a bit like what Leo imagined riding a mechanical bull would be like: Jason’s hips would buck, and Leo’s hand would tug at his hair, and the pain would make him thrash even harder. “I didn’t know! I didn’t know!” Jason’s hands were tightly balled, enough that Leo though he might actually hurt himself. “Please, please Alpha!”

“Okay!” Leo shouted, shoving Jason’s head back to the mattress to keep him still. “Okay,” this time it was a whisper, in what he hoped was a soothing tone. “I believe you,” he said softly, pushing in a little further to emphasize his point. “I know you wouldn’t really lie to me.”

“No!” Jason moaned. “No, Alpha.”

“You’re a good boy, aren’t you?” He released his grip on the older boy’s hair, running his fingers through in gentle strokes instead.

“Yes,” Jason nodded frantically. “I’m good. Please, please, I’m good.”

“I know you are, Omega.” Leo drove the affirmation home by, well, driving it home, sinking his cock all the way into Jason. He’d enjoyed the teasing while it lasted, but he didn’t actually want to upset Jason, and frankly, he kind of wanted to get to the fucking.

Jason seemed to appreciate the change of pace, lifting his head to rub against Leo’s hand and giving a satisfied moan as his hole was finally filled by something other than his own fingers. It wasn’t enough of course; there was only one thing that could really satisfy an Omega in this state, but it was a start.

“Yeah,” Leo grunted, “you’re good.” Slowly, he pulled back out, biting his lip at the loss of his Omega’s warmth around him. With a sharp thrust, he buried himself again, moaning in harmony with Jason. “So good for me, aren’t you, Omega?”

“Mmmm, yes, Alpha.” Jason’s breathing got shallower as Leo slowly picked up the pace. “I’ll be so good. I’ll give you so many strong pups.”

Aaaaaand that was when Engineer Leo looked up from his sex toy ideas and said loudly that oh, yeah, there was a point to this whole biological imperative beyond getting the two of them off. Actual Leo abruptly stopped moving, and only sort of noticed Jason’s frustrated whine.

Pups. Right. Rationally, Leo knew that was a terrible idea to entertain in the middle of a war for the fate of mankind. They were way too young, and Jason was too important to the fight to be taken off the board, and Leo was in no way ready to have kids.

But...

Leo could see it, suddenly, in perfect detail: Jason, spread-eagle, his belly swollen with Leo’s--with _their_ pups. Leo imagined what it would be like, running his hands over that pregnant belly, feeling his children kicking within. He imagined holding Jason’s hand, squeezing it tight as they welcomed their litter into the world.

It was an awful, stupid, borderline-impossible-when-you-considered-Jason’s-age thing to even consider. But in Leo’s hormone-soaked animal brain, the bit that was very much in control at the moment, it was everything he could ever want.

“Fuck yes,” he growled, driving back in with new vigor. “Say it again.”

“I want to carry your pups, Alpha!” Jason moaned. “Please,” he begged, “please give them to me!”

And that was it for any notions of self-control or forethought in Leo’s mind. There were no more reservations, there was no hesitation. There was just this: a strong young Alpha with his perfect, pliant Omega beneath him, ready and willing and eager. How had he ever doubted himself? Doubted this? If that boy back in Denver could only see himself now… Oh wait, he could, and he liked what he saw.

Thrusting became a little more difficult as his knot expanded, but Leo managed. The bitch was moaning nonstop now, all “please” and “more” and assorted incoherent noises that had Leo driving in and out with as much force as his wonderfully aching muscles would allow. His fingers found the Omega’s and he laced them together, gripping tight as he kissed the neck in front of him. Leo left a trail of of hickies from ear to shoulder, and each one solicited a new sound from the body beneath him; a symphony of pleasure and he was the conductor.

The grip around him tightened, and Leo realized with sudden satisfaction that the bitch was coming on his cock. A steady stream of what was probably Latin profanity filled the room as the Omega spent all over the sheets. The exhilaration drove Leo right to the brink. He bit into his Omega’s neck again, sparing no thought for any pain the little slut might feel. Anybody who looked at him now would know he belonged to Leo Valdez. And if the bite didn’t suffice, the smell of an Alpha all over him damn sure would.

It was that knowledge--and the pained shriek--that finally pushed Leo over the edge. He came with what could best be described as a roar, low and vicious and possessive, still latched onto his bitch’s neck, gripping his hands around the Omega’s tight enough to bruise. The Omega wailed as he was filled up, taking more joy from Leo’s orgasm that he had from his own.

The tremors lasted for a few moments afterward, Leo continuing to thrust into his Omega--into Jason, why did it feel like he was only just know remembering his name?--weakly as he rode out the orgasm and collapsed onto the broad back beneath him.

As his senses returned, Leo maneuvered them into a spooning position. Fucked out or not (and gods knew they both were), total lightweight or not, having Leo sprawled out on top of him probably wasn’t comfortable for Jason. Or maybe it was, given how he whined at being repositioned. Tangling one hand into the mop of blond hair in front of him, Leo wrapped the other around Jason’s abdomen. The last vestiges of the heat (of this round anyway; there were at least two more to look forward to if the wilderness school sex ed was to be believed) were driving him to protect the womb, where his pups might be growing even now. The thought that Jason might be carrying made his cock twitch with interest, but Leo did his best to ignore it. His rational mind was reasserting itself, which meant--unfortunately--that they needed to talk.

“Omeg--er, Jason?” he asked uneasily. It looked like Leo the Big Bad Alpha was gone now. Leo the Uneasy Teenager was back in all his what-passed-for-glory.

“Hhmmm?” Jason sounded sleepy. Which made sense; Leo felt halfway dead after what had just happened, he couldn’t imagine how exhausted his friend must be feeling.

Leo wasn’t sure how to begin. “Is this...I mean, are you ok?” Another hand reached up to take hold of Leo’s, twining together over Jason’s stomach. He felt his face heat up, which was probably the dumbest thing imaginable after what they’d just done, but he couldn’t help it.

“I…” Jason’s voice was raspy, and Leo, in hindsight, realized he should have gotten him some water before whipping his dick out. “I’m not sure but...I don’t think I’ve ever done this before.”

With those words, Leo’s heart skipped a beat. Or two. Or ten. It may or may not have been a minor cardiac arrest. Which was no worse than he deserved; bad enough he’d hopped into bed with his extremely vulnerable best friend, but he’d also apparently taken his virginity. The shame washed over him, and if it weren’t for the knot still locking them together, Leo would halfway off the nearest cliff by now.

“Shit. I--” Fuck, was he crying? He was. Like he was the one with something to cry about (The ruined friendship didn’t count; he’d been the one to ruin it, after all.). “I’m sorry.” He moved to pull his hand away, now once again acutely aware of how unworthy he was of even looking at Jason Grace, much less holding him. But Jason wasn’t letting go. In fact, he seemed to be holding on tighter.

“Sorry?” Jason tried to turn and face him. It didn’t super-duper _work_ , what with the dick still stuck in his ass, but Leo could see about a third of the other boy’s face, and it looked confused. “Leo, it’s...I’m _glad_ it was you.”

“What.” It wasn’t so much a question as it was a commentary on the absurdity of Jason’s statement.

“Anybody could have walked in here,” Jason said. “By the time I figured out what was happening to me, I was so far gone...but I know you. And I trust you. You’re one of the only people here I could trust with something like _this_. So. Don’t apologize. Actually, I should probably be apologizing to you.”

Leo was gobsmacked, to put it lightly. “But...your first time.”

Jason just shrugged. “Who better than my best friend?”

“I fucking bit you!”

“Yeah,” Jason chuckled. “I, uh, actually liked that, in case you didn’t notice. Unless--” He tried to turn again, before Leo yelped and physically held him in place, because certain bits were not meant to be stretched that way. “--sorry! But...are _you_ OK with this?”

Which was maybe the dumbest question ever. Or at least today. Because anybody with a functioning brain would know that Leo was not the wronged party here. Clearly Jason was suffering from some sort of sex madness. Hopefully it would pass soon, and Leo could go dig a hole to hide in so Zeus couldn’t fry his ass for defiling his son.

“Leo, are you hyperventilating?”

And yeah, he probably was. Christ, he could at least do Jason the favor of not dying while inside the guy. With great effort, he slowed his breathing down to normal people levels. “I’m fine,” he lied.

“You’re not.” Jason sighed. “Gods, Leo, I’m so sorry. I swear if I’d known that this was coming I’d have...I don’t know. Found somebody else.”

And Leo figured it was a mark or just how truly messed up he was that, unfit as he clearly was for this, the thought of anybody else ‘helping’ Jason through his heat made him want to growl.

“Heh, or not.” OK, so maybe he really did growl. Just a little. Sue him, he was a romantic at heart, and they were technically mated now.

“I just. Ugh,” Leo would have really like to pull away, to get some space. But he was still trapped--fuck you very much, biology. “I know I’m not exactly prime Alpha material here.”

“I’ve got some messy sheets here that say otherwise.” Godsdamnit, Leo had totally forgotten about the fucking wet spot. “Leo,” Jason interrupted his self-recrimination, “relax.” He squeezed Leo’s hand. “I think I get it. But I promise, it was good for me. What I want to know is, was it good for _you_?”

Which was a ridiculous question. Jason Grace was maybe the hottest human being Leo had ever laid eyes on. Seeing that muscled body quivering underneath him, hearing that usually steady voice beg and plead...it had been fucking heaven. Leo had literally never imagined anything could be as good!

“Well I’m glad you liked it,” Jason said, trying not to laugh. Which was Leo’s cue to realize that, yes, he’d said all that out loud.

“Fuck.”

“I hope I’m not being forward,” Jason quipped, “but that’s the general idea.”

It wasn’t a thought that made any sense to Leo. He was still sure that people like him didn’t just get to have people like Jason. But Jason didn’t seem to agree. “So you’re really cool with this?” he asked uncertainly, “with...me?”

Enough of Jason’s face was visible to make out the smirk. “Do have to write up an itemized list of everything I’d like you to do to me before you believe it?” And oh hell, Jason was rocking back on Leo’s newly interested cock. “Should I start with how I was really into the spanking? Or maybe you wanna hear about the chains I’m definitely getting once I can walk around again?”

Leo groaned. “You keep talking like that, I’m gonna gag you,” he threatened, lightly smacking Jason’s thigh.

“Don’t have a gag, I’m sad to say,” Jason turned his neck as far as it would go to face Leo. “I guess you’ll have to think of another way to shut me up.”

Leaning over to capture Jason’s lips, Leo decided that maybe this whole mess wasn’t so bad after all.

**Author's Note:**

> I meant for this story to be a quick 800 words of porn to help me through my block on the next chapter of the Star Wars AU. Leo's brain had other ideas. Let me know if you spot any mistakes (besides "all of it"), as I was pretty drunk while writing, proofreading, and posting this.


End file.
